Local Hazard Mitigation Plan

What is a Local Hazard Mitigation Plan?The Federal Emergency Management Agency (FEMA) requires that public agencies have a plan to mitigate natural hazard impact on its daily operations. For the Santa Clara Valley Water District (SCVWD) its core operations provide the following services/products to the public: Clean and reliable supply of water; protection from flooding; and environmental stewardship.

Why this webpage?To comply with FEMA direction, the water district has this webpage as one method to capture the public’s view on the our hazard mitigation plan that is an annex to the multi-jurisdictional local hazard mitigation plan developed by the Association of Bay Area Governments (ABAG http://quake.abag.ca.gov/)

What is your role as a member of the community?As a member of the community, you have the opportunity to inquire and provide feedback on the strategies (hazard mitigation activities) and related activities that the district currently funds with the goal to mitigate adverse impact on its operations by natural hazards.

Who is the Santa Clara Valley Water District contact?To provide your input on the strategies or for further information, please contact Juan Ledesma, Office of Emergency Management at (408) 265-2607, ext. 3172 or e-mail at jledesma@valleywater.org

The information below provides more details on hazard assessment and mitigation activities by the water district:

Hazard and Risk AssessmentThe ABAG multi-jurisdictional Local Hazard Mitigation Plan, lists nine hazards that affect the Bay Area: five related to earthquakes (faulting, shaking, earthquake induced landslides, liquefaction and tsunamis) and four related to weather (flooding, landslides, wildfires and drought). Because the District service area is the same as the political boundaries of Santa Clara County-- encompassing a broad geographic/geological/climatic area--all hazards that affect the county are also of concern to the district.

Based on information obtained from the California Geological Survey, FEMA, ABAG and 2004 District Water Infrastructure Reliability Project, the Number of Critical District Facilities Susceptible to various hazards are as follows:

Earthquake Faulting Potential – According to the CGS Alquist-Priolo Earthquake Fault Zone information on the ABAG website, SCVWD pipelines cross a number of faults, including the Calaveras, Shannon-Monte Vista, and Warm Springs fault zones. Portions of the SCVWD Coyote and Anderson Dams are also susceptible to faulting potential on either the Calaveras or Silver Creek Fault zones.

Earthquake Shaking Potential – All of the SCVWD facilities are susceptible to a moderate to strong category of ground shaking potential, due to the close proximity of the San Andreas, Sargent, Berocal, Monte Vista–Shannon, Coyote Creek, Silver Creek, Warm Springs, Hayward, or Calaveras faults.

Earthquake Liquefaction Susceptibility – The majority of Santa Clara Valley is not susceptible to liquefaction. The areas of higher liquefaction susceptibility includes SCVWD pipelines located in the extreme northwest area of the county adjacent to the southern end of the San Francisco Bay, and certain areas adjacent to the east side of the valley floor extending northwestward from the San Benito County line to the east-west margin of higher liquefaction potential described above. In addition, SCVWD pipelines are susceptible to liquefaction at many creek crossings. Detailed seismic stability assessments are currently being performed on four SCVWD dams (Almaden, Anderson, Calero and Guadalupe) which will also address liquefaction potential in the dam foundations; similar analyses may be performed for other SCVWD dams in the near future.

Earthquake Dam Seismic Stability - Detailed seismic stability assessments are currently being performed on four SCVWD dams; similar analyses may be performed for other SCVWD dams in the near future.

Earthquake-induced landslides – A number of SCVWD pipelines in the more mountainous portions of the county are located in earthquake-induced landslide zones. The Penitencia Water Treatment Plant is also located in an earthquake induced landslide zone.

FEMA Flood Zones – 15 facilities are located in areas of “undetermined but possible flood hazards”

Flooding and effects of flooding – A number of SCVWD pipelines are partially located in flood zones and are subject to damage by erosion or inundation.

Wildfire Threat Areas – Two SCVWD facilities (Coyote and Uvas dams) are subject to very high wildfire threat; 1 facility (Anderson Dam) is located in a high threat area; and 17 other SCVWD facilities are subject to moderate wildfire threat.

Wildland-Urban Interface Fire Threat – 13 SCVWD facilities.

Drought – Of the 139 miles of pipeline operated by the District, none are subject to damage due to drought. The District maintains in-ground water storage, above ground storage in reservoirs and imports water through State and Federal water projects.

Mitigation Activities and PrioritiesAs a participant in the ABAG multi-jurisdictional planning process, SCVWD staff helped in the development and review of the comprehensive list of mitigation strategies in the overall multi-jurisdictional plan. District staff further reviewed all of the mitigation strategies at meetings on Aug. 28, 2006 and Sept. 13, 2006. Assignment of priorities was made based on mainly staff and management feedback, which took into consideration of technical and administrative feasibility, political acceptability, social appropriateness, legal and economic soundness, and sensitivity to the environment and heritage. In 2009, the identification of staff to review the mitigation strategies was in part provided by the 2007 excel sheet and in large part by the new OES team members making the assignments. In 2009, these very strategies were updated to reflect current state of mitigation efforts.

Over time, the district is committed to developing better hazard and risk information to use in making necessary trade-offs on an on-going basis. While the district cannot create a disaster proof region, it does and will continue to contribute to improving resistance to disasters in the areas it serves. This plan identified about 70 existing strategies and over 30 very high and high priority mitigation strategies for which funding was needed.

The district will use established and proven mechanisms to continue support existing mitigation strategies identified and pursue funding for strategies having very high or high priorities in this Annex. The principal means for project approval and implementation are the district’s Capital Improvement Plan (CIP) and annual budget. The CIP is an annual, comprehensive review of asset investments required over a 10-year period to ensure adequate water resources, maintain clean, safe water and meet the present and future needs of district customers. The vulnerability of key assets to natural disasters identified in this annex will be considered in future asset investments strategies.

In addition, as the district assesses infrastructure needs through the asset management planning, performance audits or other efforts, additional high or very high priority mitigation strategies may emerge and trigger the need for funding request.